U.S. patent application number 14/496595 was filed with the patent office on 2015-04-30 for facility selection supporting method and facility selection supporting device.
The applicant listed for this patent is FUJITSU LIMITED. Invention is credited to Tetsuya KASHIWAGI, Yuichi Matsufuji.
Application Number | 20150120227 14/496595 |
Document ID | / |
Family ID | 52996341 |
Filed Date | 2015-04-30 |
United States Patent
Application |
20150120227 |
Kind Code |
A1 |
KASHIWAGI; Tetsuya ; et
al. |
April 30, 2015 |
FACILITY SELECTION SUPPORTING METHOD AND FACILITY SELECTION
SUPPORTING DEVICE
Abstract
A facility selection supporting device calculates a total
current value of consumers located in and after a certain power
supply section on the way from a distribution substation to a
particular consumer and outputs a recommended distribution facility
for the power supply section based on the calculated total current
value.
Inventors: |
KASHIWAGI; Tetsuya;
(Fukuoka, JP) ; Matsufuji; Yuichi; (Fukuoka,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FUJITSU LIMITED |
Kawasaki-shi |
|
JP |
|
|
Family ID: |
52996341 |
Appl. No.: |
14/496595 |
Filed: |
September 25, 2014 |
Current U.S.
Class: |
702/64 |
Current CPC
Class: |
Y04S 10/50 20130101;
H02J 3/005 20130101; H02J 13/00006 20200101; H02J 3/003 20200101;
H02J 3/00 20130101; Y02E 60/00 20130101; Y04S 10/16 20130101; Y04S
40/12 20130101; G01R 19/0092 20130101; H02J 13/00034 20200101; H02J
13/0017 20130101 |
Class at
Publication: |
702/64 |
International
Class: |
G01R 19/00 20060101
G01R019/00; G01D 4/02 20060101 G01D004/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 31, 2013 |
JP |
2013-227713 |
Claims
1. A non-transitory computer-readable recording medium having
stored therein a program for causing a computer to execute a
process, the process comprising: calculating a total current value
of consumers located in and after a certain power supply section on
the way from a distribution substation to a particular consumer;
and outputting a recommended distribution facility for the power
supply section based on the calculated total current value.
2. The non-transitory computer-readable recording medium according
to claim 1, wherein the recommended distribution facility has the
minimum allowable current value, the minimum cost, or the minimum
distribution wire diameter out of the distribution facilities
having allowable current values exceeding the total current
value.
3. The non-transitory computer-readable recording medium according
to claim 1, wherein the recommended distribution facility has an
allowable current value equal to or larger than the resultant of
adding a margin to the total current value.
4. The non-transitory computer-readable recording medium according
to claim 1, wherein the total current value is calculated at a
plurality of time points in respective certain periods, and the
outputting includes outputting the distribution facility having an
allowable current value corresponding to the total current value
having the maximum absolute value out of the total current values
calculated in the respective certain periods.
5. The non-transitory computer-readable recording medium according
to claim 1, wherein the total current value is calculated at a
plurality of time points in respective certain periods, and the
process further comprises identifying a section where the absolute
values of the total current values are equal to or larger than a
threshold and the time points, at which the total current values
are calculated, consecutively exist, and when the identified
section is equal to or larger than a certain time period, the
outputting includes outputting a distribution facility having an
allowable current value larger than the total current values
calculated at the time points in the section.
6. The non-transitory computer-readable recording medium according
to claim 1, wherein the total current value is calculated at a
plurality of time points in respective certain periods, and the
process further comprises identifying an interval between the time
points when the absolute value of the total current value is equal
to or larger than a threshold, and when the identified interval is
equal to or smaller than a certain time period, the outputting
includes outputting a recommended distribution facility by using
the total current value having an absolute value equal to or larger
than a threshold and the identified interval between the time
points when the total current values are calculated is equal to or
smaller than a certain time period.
7. A non-transitory computer-readable recording medium having
stored therein a program for causing a computer to execute a
process, the process comprising: calculating a total current value
of consumers located in and after a certain power supply section in
a distribution system that supplies electric power from a source of
power supply to consumers; and outputting a different suggestion
about a change in distribution facilities for the power supply
section based on a magnitude relation between an allowable current
value of the distribution facility stored in association with the
power supply section and the calculated total current value.
8. A facility selection supporting method comprising: calculating,
using a processor, a total current value of consumers located in
and after a certain power supply section on the way from a
distribution substation to a particular consumer; and outputting,
using the processor, a recommended distribution facility for the
power supply section based on the calculated total current
value.
9. A facility selection supporting device comprising: a processor;
and a memory, wherein the processor executes a process comprising:
calculating a total current value of consumers located in and after
a certain power supply section on the way from a distribution
substation to a particular consumer; and storing the total current
value in the memory; and outputting a recommended distribution
facility for the power supply section based on the total current
value in the memory.
10. A facility selection supporting device comprising: a processor;
and a memory, wherein the processor executes a process comprising:
calculating a total current value of consumers located in and after
a certain power supply section in a distribution system that
supplies electric power from a source of power supply to consumers;
and storing the total current value in the memory; and outputting a
different suggestion about a change in distribution facilities for
the power supply section based on a magnitude relation between an
allowable current value of the distribution facility stored in
association with the power supply section and the total current
value in the memory.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority of the prior Japanese Patent Application No. 2013-227713,
filed on Oct. 31, 2013, the entire contents of which are
incorporated herein by reference.
FIELD
[0002] The embodiments discussed herein are directed to a facility
selection supporting program, a facility selection supporting
method and a facility selection supporting device.
BACKGROUND
[0003] In distribution systems, widely used are distribution
facilities whose capacity can withstand the maximum load generated
in such distribution systems. Some already-known technologies
estimate the maximum load generated in distribution systems. With
such conventional technologies, the amount of power consumption in
a month is calculated based on the meter-reading information
acquired by an electric power company every month and the maximum
load is estimated based on the amount of power consumption in a
month. Conventional technologies are described in Japanese
Laid-open Patent Publication No. 2012-147675, for example.
[0004] With the conventional technologies, the maximum load is
estimated larger to some extent to prevent a situation in which the
maximum load exceeds the capacity of a distribution facility. If
the capacity of the distribution facility is selected, therefore,
based on the estimated maximum load, the distribution facility with
excessive capacity may be selected. In addition, the maximum load
may be estimated due to a low-voltage distributed generation system
in the distribution line. Furthermore, if the maximum load is not
estimated because a reverse power flow occurs, a facility may be
selected with a capacity smaller than the actual load.
SUMMARY
[0005] According to an aspect of an embodiment, a computer-readable
recording medium stores therein a program for causing a computer to
execute a process. The process comprises calculating a total
current value of consumers located in and after a certain power
supply section on the way from a distribution substation to a
particular consumer; and outputting a recommended distribution
facility for the power supply section based on the calculated total
current value.
[0006] The object and advantages of the invention will be realized
and attained by means of the elements and combinations particularly
pointed out in the claims.
[0007] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory and are not restrictive of the invention, as
claimed.
BRIEF DESCRIPTION OF DRAWINGS
[0008] FIG. 1 is a block diagram of the functional configuration of
a facility selection supporting device according to a first
embodiment of the present invention;
[0009] FIG. 2 is an example diagram of a distribution facility
included in a distribution system according to the first
embodiment;
[0010] FIG. 3 is an exemplary schematic diagram of the relation of
connection in the distribution system represented by distribution
system information according to the first embodiment;
[0011] FIG. 4 is an exemplary schematic diagram of the relation of
connection in the distribution system represented by the
distribution system information according to the first
embodiment;
[0012] FIG. 5A is a graph structure diagram of the relation of
connection in the distribution system according to the first
embodiment;
[0013] FIG. 5B is a graph structure diagram of the relation of
connection in the distribution system according to the first
embodiment;
[0014] FIG. 6 is an example diagram of data organization of
transformer specification information according to the first
embodiment;
[0015] FIG. 7 is an example diagram of data organization of
low-voltage line specification information according to the first
embodiment;
[0016] FIG. 8 is an example diagram of data organization of service
line specification information according to the first
embodiment;
[0017] FIG. 9 is an exemplary schematic diagram of the direction in
which an electric current flows when a reverse power flow occurs
according to the first embodiment;
[0018] FIG. 10 is a diagram for explaining determination whether
the reverse power flow occurs in a three-phase four-wire scheme
according to the first embodiment;
[0019] FIG. 11 is an example diagram of a change in a load
according to the first embodiment;
[0020] FIG. 12 is an example diagram of the peak load current and
the off-peak load current in pole transformers according to the
first embodiment;
[0021] FIG. 13 is an example diagram of the peak load current and
the off-peak load current in low-voltage lines according to the
first embodiment;
[0022] FIG. 14A is an example diagram of the peak load current and
the off-peak load current in service lines according to the first
embodiment;
[0023] FIG. 14B is an example diagram of the peak load current and
the off-peak load current in service lines according to the first
embodiment;
[0024] FIG. 14C is an example diagram of the peak load current and
the off-peak load current in service lines according to the first
embodiment;
[0025] FIG. 14D is an example diagram of the peak load current and
the off-peak load current in service lines according to the first
embodiment;
[0026] FIG. 14E is an example diagram of the peak load current and
the off-peak load current in service lines according to the first
embodiment;
[0027] FIG. 14F is an example diagram of the peak load current and
the off-peak load current in service lines according to the first
embodiment;
[0028] FIG. 15 is a flowchart of facility selection support
processing according to the first embodiment;
[0029] FIG. 16 is a block diagram of the functional configuration
of a facility selection supporting device according to a second
embodiment of the present invention;
[0030] FIG. 17 is an example diagram of a change in a load
according to the second embodiment;
[0031] FIG. 18 is an example diagram of a change in a load
according to a third embodiment of the present invention; and
[0032] FIG. 19 is an example diagram of a computer that executes a
facility selection supporting program according to the embodiments
of the present invention.
DESCRIPTION OF EMBODIMENTS
[0033] Preferred embodiments of the present invention will be
explained with reference to accompanying drawings. The embodiments
are not intended to limit the disclosed technology. The embodiments
may be appropriately combined without contradicting the processing
contents.
[a] First Embodiment
[0034] Configuration of a facility selection supporting device
[0035] FIG. 1 is a block diagram of a functional configuration of a
facility selection supporting device according to a first
embodiment of the present invention. A facility selection
supporting device 10 illustrated in FIG. 1 executes facility
selection support processing to select a distribution facility in a
distribution system.
[0036] An aspect of the facility selection supporting device 10 may
be provided as a Web server that performs the facility selection
support processing or a cloud computing that supplies services
relating to the facility selection support processing by
outsourcing. Another aspect of the facility selection supporting
device 10 may be provided by preinstalling or installing a facility
selection support processing program supplied as package software
or online software on a desired computer.
[0037] As illustrated in FIG. 1, the facility selection supporting
device 10 is communicably connected to other devices including a
client terminal 11, a smart meter 12, and devices provided at a
power transmission source 13 via a network 14. Examples of the
network 14 include desired types of wired or wireless communication
networks, such as the Internet, a local area network (LAN), and a
virtual private network (VPN). A desired number of client terminals
11 and smart meters 12 may be connected.
[0038] The client terminal 11 is a terminal device used for
externally operating the facility selection supporting device 10.
Examples of the client terminal 11 include a fixed terminal, such
as a personal computer (PC), and a mobile terminal, such as a
mobile phone, a personal handy-phone system (PHS), and a personal
digital assistant (PDA). The client terminal 11 is used by a member
of the electric power supplier, such as a person in charge and an
administrator in a distribution department.
[0039] The smart meter 12 is an electric power meter with a
communication function. The smart meter 12 is connected to a
distribution board of the consumer, for example. An aspect of the
smart meter 12 measures electric power used by the load facility of
the consumer every certain period, specifically, every 30 minutes,
for example. The smart meter 12 accumulates and measures the
electric power used by the load facility. In the description below,
the value of the accumulated and measured electric power used by
the load facility may be referred to as "the amount of power
consumption". The smart meter 12 measures the current and the
voltage of the electric power used in a certain period, for
example, every 30 minutes. The smart meter 12 transmits the amount
of power consumption, the current value, the voltage value, and the
measurement date and time at the measured consumer to the facility
selection supporting device 10. The measurement date and time
indicates, for example, the date and time when the measurement of
the amount of power consumption ends. While the smart meter 12
uploads the amount of power consumption every certain period in
this example, the smart meter 12 may upload the amount of power
consumption intermittently. The smart meter 12 may upload the
amount of power consumption not actively but in response to a
request from the facility selection supporting device 10.
[0040] The power transmission source 13 is an electric power
facility that supplies the electric power to a distribution system.
Examples of the power transmission source 13 include a power plant,
a distribution substation, and any place along a high-voltage
distribution line. In the present embodiment, a later-distribution
substation corresponds to the power transmission source 13. A
device provided in the power transmission source 13 periodically
measures the voltage supplied to the distribution system and the
measurement date and time thereof and transmits the information of
the measured voltage and the measurement date and time to the
facility selection supporting device 10. The device provided in the
power transmission source 13 measures the value of the voltage
supplied to the distribution system together with the measurement
date and time thereof and periodically transmits the value and the
measurement date and time to the facility selection supporting
device 10, for example. Alternatively, the device provided in the
power transmission source 13 may transmit every certain period
pieces of information on the voltage supplied to the distribution
system measured at times in a certain period. The device provided
in the power transmission source 13 may also transmit every certain
period the voltage supplied to a distribution system and the
measurement date and time thereof to the facility selection
supporting device 10, for example, every 30 minutes when the smart
meter 12 uploads the amount of power consumption.
[0041] The facility selection supporting device 10 includes a
communication interface (I/F) unit 20, a display unit 21, an input
unit 22, a storage unit 23, and a control unit 24. The facility
selection supporting device 10 may include various types of
functional units included in a known computer besides the
functional units illustrated in FIG. 1.
[0042] The communication I/F 20 controls communications with other
devices including the client terminal 11, the smart meter 12, and
the devices provided at the power transmission source 13, for
example. Examples of an aspect of the communication I/F 20 include
a network interface card, such as a LAN card. The communication I/F
20, for example, receives various types of information, such as
various types of instruction information, from the client terminal
11 and transmits image data of various types of screens from the
facility selection supporting device 10 to the client terminal
11.
[0043] The display unit 21 is a display device to display various
types of information. Examples of the display unit 21 include a
display device such as a liquid crystal display (LCD) and a cathode
ray tube (CRT). For example, the display unit 21 displays various
types of screens such as a investigation target specifying screen
and a deteriorated point screen.
[0044] The input unit 22 serves as an input device used for
inputting various types of information. Examples of the input unit
22 include an input device such as a mouse and a keyboard. The
input unit 22 receives an operation input from an administrator who
administrates the system and inputs the received operation
information that represents the details of the operation input to
the control unit 24.
[0045] The storage unit 23 serves as a storage device to store
therein the operating system (OS) and various types of computer
programs executed in the control unit 24 such as a computer program
that executes later-described facility selection support
processing. Examples of an aspect of the storage unit 23 include a
semiconductor memory device, such as a flash memory, and a storage
device, such as a hard disk and an optical disc. The storage unit
23 is not limited to the types of storage devices described above
and may be a random access memory (RAM).
[0046] The storage unit 23 stores therein the data used for the
computer program executed in the control unit 24 such as
distribution system information 30, distribution voltage
information 31, power consumption information 32, and facility
specification information 33. The storage unit 23 may also store
therein other electronic data besides the information described
above.
[0047] Examples of the distribution facility in the distribution
system include a facility "unit" relating to one position and a
facility "span" relating to two positions. FIG. 2 is an example
diagram of the distribution facility included in the distribution
system. Examples of the unit include the power pole P, a switch SW,
and the pole transformer TR. In addition to this, the concept of
the unit also includes the distribution substation SS, a step
voltage regulator (SVR), various types of meters, such as the smart
meter 12, and a manhole and a hand hole provided under the ground,
none of which is illustrated.
[0048] Examples of the span include an electric wire WH provided to
a high-voltage system that transmits high-voltage power between the
SS and the pole transformer TR, that is, what is called a
"high-voltage line". Examples of the span also include an electric
wire WL provided to a section between the pole transformer TR and a
service line in a low-voltage system that transmits low-voltage
power between the pole transformer TR and the load facility of the
consumer, that is, what is called a "low-voltage line". Examples of
the span also include an electric wire provided to a section
between the service line and the load facility, that is, what is
called a "service line". Examples of the span also include a cable
buried in the ground. A plurality of (e.g., three or two) electric
wires W, such as the high-voltage lines WH and the low-voltage
lines WL, provided between the power poles P may be collectively
considered as a span.
[0049] Referring back to FIG. 1, the distribution system
information 30 is data containing information relating to
facilities such as a unit and a span in the distribution system.
For example, the distribution system information 30 contains
information relating to the relation of connection, positions,
types, articles, specifications, and attributes of facilities in
the distribution system. The distribution system information 30 may
consist of a plurality of tables. The distribution system
information 30 may also consist of different tables such as a table
of information on the relation of connection of facilities, a table
of information on the positions of facilities, a table of
information on the types, specifications, and attributes of
facilities.
[0050] Examples of the attributes stored in the distribution system
information 30 include, in the case of the span, an article, a
thickness, a material, a length, a resistance per unit (m), and a
reactance per unit (m) of the span. Examples of the attributes may
also include, in the case of the unit, the article and performance
of the unit. For example, if the unit serves as a transformer, the
attribute may be electrical characteristics such as the capacity
and the voltage of a transformer. The attribute information is used
for calculating each distribution load in the distribution facility
in the distribution system, for example.
[0051] The distribution system information 30 includes positional
information associated with each distribution facility in the
distribution system. For example, the distribution system
information 30 contains, in the case of the unit, one piece of
positional information associated with the unit and, in the case of
the span, two pieces of positional information associated with the
span.
[0052] In the present embodiment, the relation of connection of
distribution facilities in the distribution system are managed by
using a connection "node" at which facilities are electrically
connected to each other and a facility "branch" determined by a
plurality of connections.
[0053] Examples of the node include a connection of the
high-voltage line WH and the switch SW illustrated in the enlarged
view D1 in FIG. 2, a connection of the high-voltage line WH and the
pole transformer TR, and a connection of the pole transformer TR
and the low-voltage line WL. In addition to this, the concept of
the node also includes a point at which a high-voltage line WH21a
and a high-voltage line WH21b are connected illustrated in the
enlarged view D2 in FIG. 2. Specifically, even when the
high-voltage line WH21a and the high-voltage line WH21b are hung by
a power pole P serving as a through pole, the high-voltage line
WH21a and the high-voltage line WH21b are considered to be
electrically connected. A point at which the high-voltage lines WH
are connected is considered to be a virtual node.
[0054] Examples of the branch include various types of distribution
facilities including the power pole P, the high-voltage line WH,
the switch SW, the pole transformer TR, and the low-voltage line WL
illustrated in FIG. 2. In addition to this, the concept of the
branch also includes the SS, the service line, the smart meter 12,
and the load facility, none of which is illustrated. Distribution
facilities positioned at an end, such as the SS and the load
facility, may have one node alone.
[0055] Referring back to FIG. 1, the distribution system
information 30 contains identifying information of the node and
branch of a distribution facility associated with each distribution
facility in the distribution system. Tracing the identifying
information of the node and branch of a particular distribution
facility clarifies the relation of connection of the distribution
facility in the distribution system.
[0056] FIGS. 3 and 4 are exemplary schematic diagrams of the
relation of connection in the distribution system represented by
distribution system information. FIG. 3 schematically illustrates
the relation of connection among the distribution substation SS,
the high-voltage line WH, and six low-voltage lines WL1 to WL6. The
high-voltage line WH is connected to the distribution substation SS
and the high-voltage power is supplied by a three-phase three-wire
scheme using three wires, for example. The high-voltage line WH is
provided on the power poles P and connected to the low-voltage
lines WL1 to WL6 through the pole transformers TR1 to TR6. The pole
transformers TR1 to TR6 are hereinafter also referred to as banks
#1 to #6. The pole transformers TR1 to TR6 are connected to the
high-voltage line WH and supply low-voltage power acquired by
decreasing the high-voltage power by a certain voltage value to the
low-voltage lines WL. The low-voltage lines WL may adopt any wiring
scheme out of single-phase two-wire, single-phase three-wire,
three-phase three-wire, and three-phase four-wire. For example, the
pole transformers TR1 to TR6 are connected to two out of the three
wires of the high-voltage line WH and supply a low-voltage power
acquired by decreasing the high-voltage power by to the low-voltage
lines WL. The low-voltage lines WL are also provided on the power
poles P and are connected to the service lines at the power poles
P, which supplies the electric power to the consumers through the
service lines. FIG. 3 illustrates that a service line AL is
connected to a low-voltage line WL6 and the electric power is
supplied through the service line AL.
[0057] FIG. 4 schematically illustrates the relation of connection
between the low-voltage lines and the consumers. The consumers are
connected to the low-voltage lines WL1 to WL6 through
not-illustrated service lines AL, respectively. FIG. 4 illustrates
that six houses of consumers having a contract ampere of 60 A are
connected to the power pole P1 on the low-voltage line WL1. FIG. 4
also illustrates that five houses of consumers having a contract
ampere of 60 A are connected to the power pole P2 on the
low-voltage line WL1. FIG. 4 also illustrates that six houses of
consumers having a contract ampere of 60 A are connected to the
power pole P3 on the low-voltage line WL1. FIG. 4 also illustrates
that five houses of consumers having a contract ampere of 60 A are
connected to the power pole P4 on the low-voltage line WL1. FIG. 4
also illustrates that six houses of consumers having a contract
ampere of 60 A are connected to the power pole P5 on the
low-voltage line WL1. FIG. 4 illustrates the number of consumers
connected to a transformer (a bank).
[0058] FIGS. 5A and 5B are graph structure diagrams of the relation
of connection in the distribution system. FIGS. 5A and 5B
illustrate the graph structures of the relation of connection in
the distribution system illustrated in FIGS. 3 and 4. FIGS. 5A and
5B illustrate the distribution facilities and their connections,
that is, the nodes and branches. FIGS. 5A and 5B also illustrate
IDs that is the identifying information provided in association
with the nodes and branches. FIGS. 5A and 5B illustrate the IDs of
the nodes and branches each have a character string with which the
type of the facility can be identified, such as "SS" representing a
distribution substation, "PO" representing a power pole, and "LL"
representing a consumer, at the head of the character string
constituting the ID. For example, the high-voltage line WH is
connected to the distribution substation at the node having the ID
"SS001N01". The high-voltage line WH is also connected to the pole
transformers TR1 to TR6 at the nodes having the IDs "PO0001B11",
"PO0002B21", "PO0003B31", "PO0004B41", "PO0005B51", and
"PO0006B61", respectively. The pole transformers TR1 to TR6 are
connected to the consumers through the low-voltage lines WL. For
example, the pole transformer TR1 is connected to the low-voltage
line WL at the node having the ID "PO0001B12". As illustrated in
the enlarged view D3 in FIG. 5A, the low-voltage line WL is
connected to the service lines AL1 to AL6 at the node having the ID
"PO0007B13". The service lines AL1 to AL6 are connected to the
consumers at the nodes having the IDs "LL0702B01", "LL0801B01",
"LL0802B01", "LL0901B01", "LL0902B01", and "LL1001B01",
respectively.
[0059] Referring back to FIG. 1, the distribution voltage
information 31 includes various types of information on the
electric power supplied to the distribution system. For example,
the distribution voltage information 31 includes the information
relating to the voltage and the measurement date and time of the
power distribution to the distribution system periodically uploaded
by the device provided on the distribution substation SS or the
high-voltage distribution line as the power transmission source
13.
[0060] The power consumption information 32 is data containing
various types of information relating to the electric power
received from the smart meter 12 installed at consumers. For
example, the power consumption information 32 stores therein the
information relating to the amount of power consumption of the
consumers, the current value, the voltage value, and the
measurement date and time periodically notified by the smart meter
12.
[0061] The facility specification information 33 is data containing
various types of information relating to the specifications of
various types of distribution facilities that can be used in the
distribution system. In the present embodiment, the facility
specification information 33 contains various types of information
relating to the specification of the distribution facilities for
each type of facility. In the present embodiment, for example, the
facility specification information 33 is categorized into three
types of information: transformer specification information 33A,
low-voltage line specification information 33B, and service line
specification information 33C.
[0062] The transformer specification information 33A is data
containing various types of information relating to the
specification of the transformer that can be used in the
distribution system. For example, the transformer specification
information 33A contains information relating to the specification
of the transformer for each type of the transformer.
[0063] FIG. 6 is an example diagram of data organization of the
transformer specification information. The transformer
specification information 33A includes a table in which items
including the article, the specification, and the allowable current
are associated with one another, for example. The article item is a
field storing the identifying information representing the type of
the transformer. The identifying information is determined for each
type of the transformer and represents the model of the
transformer, for example. The article item stores therein the
identifying information representing the type of the transformer.
The specification item is a field storing various types of
information relating to the specification of the transformer. In
the present embodiment, the specification item includes the iron
core item and the capacity item. The iron core item is a field
storing the type of the member mainly constituting the iron core of
the transformer. The capacity item is a field storing the
electrical capacity allowed by the transformer. The allowable
current item is a field storing the current value allowed by the
transformer. The example in FIG. 6 illustrates that the transformer
of the article "TR-0030" includes the iron core made of a "steel
sheet", a capacity of "30 kVA", and an allowable current of "228
A".
[0064] The low-voltage line specification information 33B is data
containing various types of information relating to the
specification of the wire that can be used in the distribution
system as a low-voltage line. For example, the low-voltage line
specification information 33B contains information relating to the
specification of the wire that can be used in the distribution
system for each type of the wire.
[0065] FIG. 7 is an example diagram of data organization of the
low-voltage line specification information. The low-voltage line
specification information 33B includes a table in which items
including the article, the specification, and the allowable current
are associated with one another, for example. The article item is a
field storing the identifying information representing the type of
the wire that can be used as a low-voltage line. The identifying
information is determined for each type of the wire and represents
the model of the wire, for example. The article item stores therein
the identifying information representing the type of the wire. The
specification item stores therein various types of information
relating to the specification of the wire. In the present
embodiment, the specification item includes the core wire item, the
covering item, and the size item. The core wire item stores therein
the type and the structure of the member mainly constituting the
conductor in which the current flows existing in the center of the
wire. The covering item is a field storing the type and the
structure of the member covering the wire. The size item is a field
storing information representing the thickness of the core wire. In
the present embodiment, the information representing the thickness
of the core wire stores therein cross-sectional area of the core
wire. Alternatively, the information representing the thickness of
the core wire may store therein codes representing the diameter or
radius of the cross sectional surface of the core wire, or codes
representing the thickness of the core wire. The allowable current
item is a field storing the current value allowed by the wire. The
example in FIG. 7 illustrates that the wire of the article
"LL-01025" includes the core wire made of a "steel core aluminum
stranded wire", the covering made of a "polyethylene insulated
wire", has a size of "25 mm2" and an allowable current of "85
A".
[0066] The service line specification information 33C is data
containing various types of information relating to the
specification of the wire that can be used in the distribution
system as a service line. For example, the service line
specification information 33C contains information relating to the
specification of the wire that can be used in the distribution
system for each type of the wire.
[0067] FIG. 8 is an example diagram of data organization of the
service line specification information. The service line
specification information 33C includes a table in which items
including the article, the specification, and the allowable current
are associated with one another, for example. The article item is a
field storing the identifying information representing the type of
the wire that can be used as a service line. The article item
stores therein the identifying information representing the type of
the wire. The specification item is a field storing various types
of information relating to the specification of the wire. In the
present embodiment, the specification item includes the core wire
item, the covering item, and the size item. The core wire item
stores therein the type and the structure of the member mainly
constituting the conductor in which the current flows existing in
the center of the wire. The covering item is a field storing the
type and the structure of the member covering the wire. The size
item is a field storing information representing the thickness of
the core wire. In the present embodiment, if the core material has
a single-wire structure, the size item stores therein the diameter
of the core wire. If the core material has a stranded-wire
structure, the size item stores therein the cross-sectional area of
the core wire. The allowable current item is a field storing the
current value allowed by the wire. The example in FIG. 8
illustrates that the wire of the article "SL-01020" includes the
core wire made of a "single wire", the covering made of a
"polyvinyl chloride insulated wire for leading-in", the size
represents a diameter of "2 mm" because the wire is a single wire,
and has an allowable current of "25 A".
[0068] The control unit 24 includes an internal memory that stores
therein a computer program and controls data defining various types
of processing procedures and performs various types of processing
by using these pieces of data. As illustrated in FIG. 1, the
control unit 24 includes an acquiring unit 40, a calculating unit
41, and an output unit 42.
[0069] The acquiring unit 40 is a processing unit to acquire
various types of information. For example, the acquiring unit 40
acquires the voltage of the high-voltage distribution line led from
the distribution substation SS as the voltage information of the
distribution system. An aspect of the acquiring unit 40 acquires
the voltage and the measurement date and time of a three-wire
distribution line in the distribution system updated by the device
provided in the high-voltage distribution line led from the
distribution substation SS. The measurement date and time may
indicate the date and time when the data is uploaded. The acquiring
unit 40 additionally registers the acquired voltage and the
measurement date and time of the distribution line in the
distribution voltage information 31.
[0070] For example, the acquiring unit 40 acquires the amount of
power consumption, the current value, the voltage value, and the
measurement date and time from the smart meter 12. An aspect of the
acquiring unit 40 acquires the amount of power consumption and the
measurement date and time updated by the smart meter 12 connected
to the load facility at each consumer. The measurement date and
time may indicate the date and time when the data is uploaded. The
acquiring unit 40 additionally registers the facility ID, the
amount of power consumption, the current value, the voltage value,
and the measurement date and time of the load facility connected to
the smart meter 12 in the power consumption information 32. An
assumption is made that each smart meter 12 updates the data every
certain period, specifically, every 30 minutes, for example. The
power consumption information 32 contains the load information on
the power consumption facility acquired every certain period. The
power consumption information 32, for example, registers therein
the data for each smart meter 12 in the cycle of a time
corresponding to the sum of an interval of meter-reading that
causes the smart meter 12 to transmit the reading result of the
amount of power consumption, and a transmission delay time between
the power consumption information 32 and the facility selection
supporting device 10.
[0071] The capacity of various types of distribution facilities
used in the distribution system withstands the maximum load
(hereinafter, also referred to as a peak load) generated in the
distribution system. The load in the distribution system changes
over time depending on the amount of power consumed by the load
facility at each consumer who tends to temporarily use the power
connected to the distribution system. If a consumer is connected to
the distribution system, the usual load is moderate and the higher
peak load appears when the consumer uses the power. The power
generated in widely used low-voltage distributed generation
systems, as represented by a home photovoltaic generation system,
are partially substituted for the amount of power consumption. This
causes the value of the amount of power consumption in a month by a
consumer acquired by meter-reading by an electric power company
appear smaller than the actual power consumption. This leads to
calculating the peak load current smaller than the actual value if
the maximum load generated in the distribution system is estimated
based on the monthly amount of power consumption, with the
conventional technology, for example. This may lead to the
determination that the facility having a smaller capacity than the
actual load has no problem. For another example, a reverse power
flow occurs from a distributed generation system provided in the
consumer to the distribution system of an electric power supplier.
The electric power flowing bidirectionally, as described above,
between the distribution substation and the load facility increases
the fluctuation in facilities in low-voltage system due to the
reverse power flow generated. Diversified life styles of consumers
or diversified load facilities also change the pattern of power
consumption. This makes it hard to properly calculate the capacity
of various types of distribution facilities used in distribution
systems.
[0072] FIG. 9 is an exemplary schematic diagram of the direction an
electric current flows when a reverse power flow occurs. For
example, if a distributed generation system is provided at a
consumer connected to the bank #6, the reverse power flow may occur
from the consumer to the pole transformer TR6 on the low-voltage
line WL6, as represented with the arrows. The reverse power flow
may occur along the low-voltage line between the banks. The example
of FIG. 9 illustrates that the reverse power flow occurs from the
pole transformer TR6 to the transformer TR5. As described above,
when the reverse power flow occurs in the distribution system, the
current flowing from the consumer resulting from a reverse power
flow may be larger than the usual current flowing toward the
consumer.
[0073] The calculating unit 41 calculates the load status in the
distribution system. For example, the calculating unit 41
calculates the total current value of the consumers located in and
after a certain power supply section on the way from the
distribution substation to a particular consumer. The calculated
total current value represents the load status of the certain power
supply section. In the present embodiment, the smart meter 12
measures the amount of power consumption, the current value, and
the voltage value at the consumer every 30 minutes, for example.
The data of the measured results at a plurality of time points for
each consumer is therefore stored in the power consumption
information 32. The calculating unit 41 sums up the current values
of the consumers measured time points of which are included in a
certain period, for example, 30 minutes and calculates the total
current value in each certain period.
[0074] More specifically, the calculating unit 41 reads the
information used for calculating the load status from the storage
unit 23. For example, the calculating unit 41 reads the current
values of the consumers measured time points of which are included
in a certain period, for example, 30 minutes from the power
consumption information 32.
[0075] The calculating unit 41 determines whether any reverse power
flow occurs at a consumer. Any scheme may be used for determining
whether a reverse power flow occurs. For example, the determination
can be made based on the shift of the phase in the voltage or the
current of each low-voltage line WL. Specifically, if the
low-voltage line WL has a three-phase four-wire scheme, the
direction of the power flow, that is, whether the current flows
from the distribution system to the consumer (a forward power flow)
or the current flows from the consumer to the distribution system
(the reverse power flow), can be determined based on the voltage or
the current of each wire. FIG. 10 is a diagram for explaining
determination whether the reverse power flow occurs in the
three-phase four-wire scheme. For example, the current Is flows
through the wire s, the current In flows through the wire n, the
current It flows through the wire t, and the current Ir flows
through the wire r in the three-phase four-wire scheme. The voltage
between the wire s and the wire n is Vns, the voltage between the
wire s and the wire t is Vst, the voltage between the wire s and
the wire r is Vrs, the voltage between the wire n and the wire t is
Vtn, and the voltage between the wire t and the wire r is Vtr. In
the following formula, Re ( ) represents the real part of the
elements in the bracket. Is* represents the conjugate complex
number of the current value in the s-phase and Ir* represents the
conjugate complex number of the current value in the r-phase. The
following formula can be used for determining whether the reverse
power flow occurs. With the formula, the calculation is made
assuming that In=0.
Re(VstIs*-Vtrr*)>0: the forward power flow
Re(VstIs*-Vtrr*)<0: the reverse power flow
[0076] For example, Is is 10 A, the phase is shifted behind by 90
degrees (-90.degree.), and In is 0 A. Is is 10 A, the phase is
shifted ahead by 90 degrees (+90.degree.), In is 0 A, and Ir is 0
A. Vns is 100 V and the phase is shifted behind by 60 degrees
(-60.degree.). Vtn is 100 V and the phase is shifted behind by 60
degrees (-60.degree.). Vst is 100 V and the phase is shifted behind
by 60 degrees (+120.degree.). Vtr is 200 V and the phase is 0
degree (0.degree.). Vrs is 200 V and the phase is 0 degree
(0.degree.).
[0077] With the conditions above, Vst, Is, and Is* can be
calculated as follows:
Vst = 200 { cos ( 120 .degree. ) + j sin ( 120 .degree. ) } = - 100
+ j 100 ( 3 ) 1 / 2 ##EQU00001## Is = 10 { cos ( - 90 .degree. ) +
j sin ( - 90 .degree. ) } = 0 - j 10 ( 3 ) 1 / 2 ##EQU00001.2## Is
* = 0 + j 10 ( 3 ) 1 / 2 ##EQU00001.3##
[0078] In the same manner, Vtr and Ir* can be calculated as
follows:
Vtr=200+j0
Ir*=0+j0
[0079] The value in the formula used for determining whether a
reverse power flow occurs can be calculated as follows:
Vst Is * - Vtr Ir * = ( - 100 + j 100 ( 3 ) 1 / 2 ) ( 0 + j 10 ( 3
) 1 / 2 ) - ( 200 + j 0 ) ( 0 + j 0 ) = 3000 - J 1000 ( 3 ) 1 / 2
##EQU00002## Re ( Vst Is * - Vtr Ir * ) = 3000 > 0
##EQU00002.2##
[0080] As a result, the power flow is determined to be a forward
power flow. In the present embodiment, the forward power flow is
represented by a positive value and the reverse power flow is
represented by a negative value on the basis of the current
direction toward a consumer in the distribution system. This is
provided merely for exemplary purpose and not limited to this. The
presence of the reverse power flow may be determined in a different
manner. The presence of the reverse power flow may be determined if
the voltage on the downstream side from the connection to a pole
transformer TR is higher than the upstream side therefrom in a
low-voltage line WL. The presence of the reverse power flow may
also be determined if the voltage measured at a particular consumer
is higher than the voltage measured on the upstream side from the
consumer.
[0081] The calculating unit 41 sums up the current values of the
consumers measured time points of which are included in a certain
period, for example, 30 minutes and calculates the total current
value in each certain period. The calculated total current value
represents the load generated in the distribution facility. FIG. 11
is an example diagram of a change in a load. FIG. 11 is a graph
acquired by plotting the calculated total current value for each
certain period at the end time point of each certain period. FIG.
11 illustrates an example of a chronological change in the total
current value of pole transformers TR when a low-voltage
distributed generation system such as a home photovoltaic
generation system is provided at a consumer and the total current
value of each power pole P on which a low-voltage line WL connected
to the pole transformer is provided. If a low-voltage distributed
generation system is provided at a consumer, as illustrated in FIG.
11, the total current value is negative due to the reverse power
flowing from the consumer from about 7 to 17 o'clock. The peak
current value on the negative side may be larger than the peak
current value on the positive side.
[0082] The calculating unit 41 calculates the total current value
in each certain period of the consumers located in and after a
particular distribution facility in the distribution system, for
each distribution facility in the distribution system.
[0083] The output unit 42 performs various types of outputs. The
output unit 42 outputs the recommended distribution facility for a
particular power supply section, for example. The output unit 42
calculates the total current value having the maximum absolute
value out of the total current values calculated every certain
period. Specifically, the output unit 42 calculates the total peak
current value on the positive side and the total peak current value
on the negative side based on each total current value calculated
by the calculating unit 41 in each certain period for each
distribution facility. The total peak current value on the positive
side is hereinafter also referred to as a "peak load current" and
the total peak current value on the negative side" is hereinafter
also referred to as an "off-peak load current". The example in FIG.
11 illustrates that the arrow X1 indicates a peak load current and
the arrow X2 indicates an off-peak load current. The output unit 42
compares the peak load current with the off-peak load current and
uses the one having a greater absolute value to output the
recommended distribution facility.
[0084] FIGS. 12 to 14F illustrate examples of the calculation
results of the peak load current and the off-peak load current in
the distribution facilities. FIG. 12 is an example diagram of the
peak load current and the off-peak load current in the pole
transformers. The example in FIG. 12 illustrates the peak load
current and the off-peak load current of the banks #1 to #6. The
example in FIG. 12 illustrates the articles of the transformers
used at the banks #1 to #6.
[0085] FIG. 13 is an example diagram of the peak load current and
the off-peak load current in low-voltage lines. The example in FIG.
13 illustrates the peak load current and the off-peak load current
for the low-voltage lines WL connected to the banks #1 to #6
grouped by power poles P. Referring to FIG. 4, the upward
low-voltage lines 1 represents the low-voltage lines WL provided
from the banks #1 to #6 to the respective first power poles P in
the up direction out of the low-voltage lines WL connected to the
banks #1 to #6. Referring to FIG. 4, the upward low-voltage lines 2
represents the low-voltage lines WL provided from the first power
poles P to the second first power poles P in the up direction out
of the low-voltage lines WL connected to the banks #1 to #6.
Referring to FIG. 4, the downward low-voltage lines 3 represents
the low-voltage lines WL provided from the banks #1 to #6 to the
respective first power poles P in the down direction out of the
low-voltage lines WL connected to the banks #1 to #6. Referring to
FIG. 4, the downward low-voltage lines 4 represents the low-voltage
lines WL provided from the first power poles P to the second power
poles P in the down direction out of the low-voltage lines WL
connected to the banks #1 to #6. The example in FIG. 13 illustrates
the articles of the wires used as low-voltage lines WL. In the
present embodiment, the wires used as low-voltage lines WL are
grouped into two classes, that is, an n-phase and an s/t-phase. The
wire n is used as a low-voltage line WL in the n-phase and the wire
s or the wire t is used as a low-voltage line WL in the
s/t-phase.
[0086] FIGS. 14A to 14F are example diagrams of the peak load
current and the off-peak load current in service lines. FIGS. 14A
to 14F illustrate the peak load current and the off-peak load
current in service lines AL under the banks #1 to #6 grouped by
power poles. The examples in FIGS. 14A to 14F illustrate the
service lines AL grouped by power poles P to which the service
lines AL are connected. The consumers under bank # lists the
service lines AL to the consumers connected to the power poles P
provided with the banks. Referring to FIG. 4, the consumers under
the upward poles 1 lists the service lines AL to the consumers
connected to the first power poles P from the banks #1 to #6 in the
up direction. Referring to FIG. 4, the consumers under the upward
poles 2 lists the service lines AL to the consumers connected to
the second power poles P from the banks #1 to #6 in the up
direction. Referring to FIG. 4, the consumers under the downward
poles 3 lists the service lines AL to the consumers connected to
the first power poles P from the banks #1 to #6 in the down
direction. Referring to FIG. 4, the consumers under the downward
poles 4 lists the service lines AL to the consumers connected to
the second power poles P from the banks #1 to #6 in the down
direction. The examples in FIGS. 14A to 14F illustrate the articles
of the wires used as service lines AL. In the present embodiment,
two types of wires, that is, the wire s and the wire t are used as
service lines AL. The s/t-phase corresponds to the wire s and the
wire t.
[0087] The output unit 42 compares the peak load current with the
off-peak load current and uses the one having a greater absolute
value to output the recommended distribution facility. The output
unit 42, for example, compares the peak load current with the
off-peak load current and determines the one having a greater value
as the maximum load current value. The output unit 42 selects the
distribution facility having the allowable current value
corresponding to the determined maximum load current value from the
facility specification information 33. The output unit 42 selects
the distribution facility of the article having the allowable
current value equal to or larger than the maximum load current
value and having the minimum allowable current value, for example.
If the selected distribution facility is different from the
distribution facility that is being used, the output unit 42
outputs the selected distribution facility as the recommended
distribution facility. The output unit 42 outputs screen
information displaying the information relating to the recommended
distribution facility to the client terminal 11 and enables the
client terminal to display the information on the screen. The
output unit 42 may output the maximum load current value for each
distribution facility. The output unit 42 may output the
information relating to the recommended distribution facility for
the distribution facility with an insufficient capacity. That is,
the output unit 42 does not necessarily output the information
relating to the recommended distribution facility for the
distribution facility with an excessive capacity. No problem will
occur when not replacing the distribution facility with an
excessive capacity. The output unit 42 may therefore output the
information relating to the recommended distribution facility only
for the distribution facility with an insufficient capacity.
[0088] The example in FIG. 12 illustrates that the peak load
current is determined to be the maximum load current value in the
banks #1 to #5. The off-peak load current is determined to be the
maximum load current value in the bank #6. In the bank #6, as
illustrated in FIG. 11, the reverse power flow often occurs. The
example in FIG. 12 illustrates that the article of the distribution
facility selected based on the maximum load current value is listed
as a selected article. In the banks #1 to #5, the distribution
facility of the article "TR-0100" having an allowable current value
of 762 A is selected as the distribution facility having the
allowable current value corresponding to the peak load current,
that is, the maximum load current value. By contrast, in the bank
#6, the distribution facility of the article "TR-0100" having an
allowable current value of 762 A is selected as the distribution
facility having the allowable current value corresponding to the
off-peak load current, that is, the maximum load current value.
Because the selected article "TR-0100" is different from the
distribution facility of the article "TR-0050" that is being used
in the bank #6, the output unit 42 therefore outputs the
distribution facility of the article "TR-0100" as the recommended
distribution facility. If the distribution facility is provided
based on the peak load current, then the bank #6 is provided with
the distribution facility of the article "TR-0050" having an
allowable current value of 380 A. This makes the bank #6 with the
article "TR-0050" have an insufficient capacity because the
off-peak load of the bank #6 is 480 A. The distribution facility in
the bank #6 is therefore replaced with the recommended distribution
facility, thereby preventing the distribution facility from having
insufficient capacity.
[0089] In addition, the output unit 42 selects the distribution
facility having the allowable current value corresponding to the
maximum load current value, thereby preventing the distribution
facility with an excessive capacity.
[0090] The example in FIG. 13 illustrates that "excessive capacity"
is noted on the facilities with the capacity excessive for the
maximum load current value. "Reverse power flow" is also noted on
the facilities having the off-peak load current larger than the
peak load current. For the distribution facility with an excessive
capacity, a distribution facility with the smaller allowable
current value is selected. In the downward low-voltage line 3 in
the bank #1, for example, the wire n is the article "LL-01058"
having an allowable current value of 135 A and the wire s and the
wire t are the article "LL-01120" having an allowable current value
of 195 A. The output unit 42 selects the wire of the article
"LL-01025" having an allowable current value of 85 A for the wire n
and selects the wire of the article "LL-01058" having an allowable
current value of 135 A for the wire s and the wire t. The wire n
has sufficient capacity if replaced with the wire of the article
"LL-01025" having an allowable current value of 85 A. The wire s
and the wire t also have sufficient capacities if replaced with the
wire of the article "LL-01058" having an allowable current value of
135 A. This enables the output unit 42 to select the distribution
facility that matches the load.
[0091] For the distribution facility where a reverse power flow
occurs, a distribution facility having the allowable current value
corresponding to the off-peak load current is selected. For the
wire s and the wire t used for the upward low-voltage line 2 in the
bank #6, for example, the article "LL-01058" having an allowable
current value of 135 A is selected.
[0092] The examples in FIGS. 14A to 14F also illustrate that
"excessive capacity" is noted on the facilities with the capacity
excessive for the maximum load current value, "insufficient
capacity" is noted on the facilities with the capacity insufficient
for the maximum load current value, and "the reverse power flow" is
noted on the facilities having the off-peak load current larger
than the peak load current. In the consumers under the bank #1 in
FIG. 14A, the distribution facility is determined to be the
facility having an excessive capacity, and the article "SL-01020"
having an allowable current value of 25 A is selected. For the
first customer (the first line) in the consumers under the downward
poles 4 in FIG. 14B, the present article "SL-01026" has an
allowable current value of 34 A that is insufficient for the peak
load. The article "SL-01032" having an allowable current value of
44 A is therefore selected. The service lines listed in the bank #6
in FIG. 14F all have reverse power flows and the service line
having the allowable current value corresponding to the off-peak
load current is selected.
[0093] The output unit 42 compares the peak load current with the
off-peak load current and determines the one having a greater
absolute value, that is, the total current value having the maximum
absolute value as the maximum load current value. Alternatively,
the output unit 42 may determine the resultant of adding a margin
to the maximum total current value as the maximum load current
value. The margin may be a fixed value or a rate such as 10% of the
maximum total current value. The margin may be externally set by an
administrator, for example.
[0094] The output unit 42 selects the distribution facility of the
article having the allowable current value equal to or larger than
the maximum load current value and having the minimum allowable
current value, for example. The output unit 42, however, may select
the distribution facility based on other criteria. Information on
the cost such as the price of the distribution facilities, for
example, is stored in the facility specification information 33.
The output unit 42 may select the distribution facility of the
article having the maximum load current value equal to or smaller
than the allowable current value and the smaller cost as the
corresponding distribution facility. The output unit may also
select the distribution facility of the article having the maximum
load current value equal to or smaller than the allowable current
value and a smaller diameter (size) of the distribution wire as the
corresponding distribution facility. The cost of a typical wire
increases with an increased diameter thereof. This also increases
the cost for installation. Selecting a distribution facility having
a small diameter by the output unit 42 therefore suppresses the
increase of the cost for the distribution facility.
[0095] The control unit 24 may be various types of circuits,
including integrated circuits and electronic circuits. A part of
the functional units included in the control unit 24 may be other
integrated circuits or electronic circuits. Examples of the
integrated circuits include an application specific integrated
circuit (ASIC). Examples of the electronic circuits include a
central processing unit (CPU) and a micro processing unit
(MPU).
[0096] Procedure of Processing
[0097] The following describes the procedure of facility selection
support processing performed by the facility selection supporting
device 10 according to the present embodiment. The facility
selection supporting device 10 supports the selection of the
distribution facility through the facility selection support
processing. FIG. 15 is a flowchart of the facility selection
support processing. The facility selection support processing is
started at a certain time, specifically, when the client terminal
11 instructs selection of a distribution facility, for example.
[0098] As illustrated in FIG. 15, the calculating unit 41
calculates the total current value in each certain period of the
consumers located in and after a particular distribution facility
in the distribution system, for each distribution facility in the
distribution system (Step S10). The output unit 42 calculates the
total current value having the maximum absolute value out of the
total current values calculated every certain period (Step S11).
Specifically, the output unit 42 calculates the peak current value
and the peak current value based on each total current value
calculated by the calculating unit 41 in each certain period for
each distribution facility. The output unit 42 compares the peak
load current with the off-peak load current and determines the one
having a greater absolute value as the maximum total current
value.
[0099] The output unit 42 selects the distribution facility having
the allowable current value corresponding to the maximum load
current value from the facility specification information 33 for
each distribution facility in the distribution system (Step S12).
If the selected distribution facility is different from the
distribution facility that is being used, the output unit 42
outputs the selected distribution facility as the recommended
distribution facility. The output unit 42 outputs the screen
information displaying the information relating to the recommended
distribution facility to the client terminal 11 and enables the
client terminal to display the information on the screen.
Advantageous Effects of the First Embodiment
[0100] As described above, the facility selection supporting device
10 calculates the total current value of the consumers located in
and after a certain power supply section on the way from the
distribution substation SS to a particular consumer. The facility
selection supporting device 10 outputs the recommended distribution
facility for a particular power supply section based on the
calculated total current value. This enables the facility selection
supporting device 10 to support the selection of the distribution
facility that matches the load.
[0101] The facility selection supporting device 10 determines
distribution facility having the minimum allowable current value,
the minimum cost, or the minimum diameter (size) of the
distribution wire out of the distribution facilities having the
allowable current value exceeding the total current value as the
recommended distribution facility. This enables the facility
selection supporting device 10 to recommend the distribution
facility having the smaller cost, thereby suppressing the increase
of the cost for the distribution facility.
[0102] The facility selection supporting device 10 determines the
distribution facility having the allowable current value equal to
or larger than the resultant of adding a margin to the total
current value as the recommended distribution facility. This
enables the facility selection supporting device 10 to suppress the
recommended distribution facility from being unable to correspond
to the load if the load generated in the distribution system
increases due to a change in the life style of the consumer, for
example.
[0103] The facility selection supporting device 10 outputs the
distribution facility having the allowable current value
corresponding to the total current values having the maximum
absolute value out of the total current values calculated every
certain period. This enables the facility selection supporting
device 10 to recommend the distribution facility corresponding to
the maximum load actually generated.
[b] Second Embodiment
[0104] A second embodiment according to the present invention will
be described. FIG. 16 is a block diagram of the functional
configuration of a facility selection supporting device according
to the second embodiment. The configuration of the facility
selection supporting device 10 according to the second embodiment
is substantially the same as that of the first embodiment. The
explanation will be mainly made of the differing parts.
[0105] The control unit 24 further includes, as illustrated in FIG.
16, an identifying unit 43.
[0106] Distribution facilities generate heat as a current flows and
the generated heat increases with a larger current. The temperature
of distribution facilities rises with the longer period during
which a large current flows. If the temperature of distribution
facility exceeds the allowable temperature, the distribution
facility is likely to malfunction. The allowable current of
distribution facilities is therefore determined to be a temperature
not exceeding the allowance if a current flows. Because the
distribution facilities are cooled in the period when a small
current flows, the temperature thereof hardly rises even when a
large current flows through temporarily.
[0107] The identifying unit 43 performs various types of
identification. The identifying unit 43, for example, identifies
the section where the absolute values of the total current values
are equal to or larger than a certain threshold and the time
points, at which the total current values are calculated,
consecutively exist. FIG. 17 is an example diagram of a change in a
load. The identifying unit 43, for example, identifies the section
T1 where the absolute values of the total current values reach a
threshold Th1 and the time points, at which the total current
values are calculated, consecutively exist, as illustrated in FIG.
17.
[0108] If the identified section T1 is equal to or larger than a
certain time period, for example, 2 hours or longer, the output
unit 42 selects the distribution facility having an allowable
current value larger than the total current values calculated at
the time points in the section and outputs the distribution
facility. That is, the output unit 42 selects the distribution
facility having the allowable current value larger than the total
current values in the section T1. The output unit 42, for example,
selects the distribution facility having the allowable current
value corresponding to the resultant of adding a margin to the
maximum total current value in the section T1. The margin may be a
fixed value or a ratio such as 10% of the maximum total current
value. The margin may be externally set by an administrator, for
example.
Advantageous Effects of the Second Embodiment
[0109] As described above, the facility selection supporting device
10 identifies the section where the absolute values of the total
current values are equal to or larger than a threshold Th1 and the
time points, at which the total current values are calculated,
consecutively exist. If the identified section is equal to or
larger than a certain time period the facility selection supporting
device 10 outputs the distribution facility having an allowable
current value larger than the total current values calculated at
the time points in the section. This enables the facility selection
supporting device 10 to suppress failures that are likely to be
caused by the temperature in the distribution facility exceeding
the allowable temperature.
[c] Third Embodiment
[0110] A third embodiment according to the present invention will
be described. The configuration of the facility selection
supporting device 10 according to the third embodiment is
substantially the same as that of the second embodiment and
overlapped explanation thereof will be omitted.
[0111] The identifying unit 43 in the facility selection supporting
device 10 according to the third embodiment identifies the interval
between the time points when the absolute value of the total
current value is equal to or larger than a threshold. FIG. 18 is an
example diagram of a change in a load. The identifying unit 43, as
illustrated in FIG. 18, identifies the interval T2 between the time
points when the absolute value of the total current values are
equal to or larger than the threshold Th2.
[0112] The distribution facility is cooled in the period when a
small current flows. If the interval T2 between the periods when a
large flowing current flows is long, the distribution facility is
sufficiently cooled in the interval T2. By contrast, if the
interval T2 is short, the distribution facility is not sufficiently
cooled in the interval T2, thus the temperature of the distribution
facility increases.
[0113] The output unit 42 therefore outputs the recommended
distribution facility as follows if the identified interval T2 is
shorter than a certain time period, for example, an hour or
shorter. That is, the output unit 42 uses the total current value
having the absolute value equal to or larger than the threshold Th2
and the interval T2 between the time points when the total current
values are calculated is equal to or smaller than a certain time
period to output the recommended distribution facility. If the
identified interval T2 is equal to or smaller than a certain time
period, the output unit 42 uses the total current value in the
section where the absolute values of the total current values are
equal to or larger than the threshold Th2 before and after the
interval T2 to select the distribution facility. The output unit
42, for example, selects the distribution facility having the
allowable current value corresponding to the maximum total current
value in the section where the absolute values of the total current
values are equal to or larger than the threshold Th2 before and
after the interval T2.
Advantageous Effects of the Third Embodiment
[0114] As described above, the facility selection supporting device
10 identifies the interval between the time points when the
absolute values of the total current values are equal to or larger
than a threshold. If any identified interval is equal to or smaller
than a certain time period, the facility selection supporting
device 10 uses the total current value having the absolute value
equal to or larger than a threshold and the identified interval
between the time points when the total current values are
calculated is equal to or smaller than a certain time period to
output the recommended distribution facility. This enables the
facility selection supporting device 10 to suppress failures that
are likely to be caused by the temperature in the distribution
facility exceeding the allowable temperature.
[c] Fourth Embodiment
[0115] While the explanations have been made of the embodiments of
the disclosed device, the present invention may be embodied as
various difference aspects besides the embodiments above. The
following describes other embodiments included in the present
invention.
[0116] In the embodiment described above, the smart meter 12
transmits the current value used by a consumer in each certain
period. This is provided merely for exemplary purpose and is not
limited to this. If the smart meter 12 does not transmit the
current value, the current value used by a consumer may be
calculated based on the amount of power consumption and the
voltage. If the smart meter 12 is not provided, the current value
may be calculated based on the specification of the load facility
or the power source facility connected to the distribution
system.
[0117] In the embodiment described above, the smart meter 12
transmits various types of information to the facility selection
supporting device 10 through the network 14. This is also provided
merely for exemplary purpose and is not limited to this. The smart
meter 12 may store therein the current value in each certain period
used by a consumer, and an electric power company may collect the
voltage value data at the monthly meter-reading.
[0118] In the embodiment described above, the recommended
distribution facility is output. This is also provided merely for
exemplary purpose and is not limited to this. A different
suggestion about replacement of distribution facility in the power
supply section may be output based on the magnitude relation
between the allowable current value of the distribution facility
stored in association with the power supply section and the
calculated total current value. Alternatively, a message may be
output that prompts an administrator, for example, to replace the
distribution facility if the allowable current value of the
distribution facility in the distribution system is smaller than
the total current value.
[0119] Distribution and Integration
[0120] The components of each device illustrated in the drawings
are not necessarily physically configured as illustrated. In other
words, the specific aspects of distribution and integration of each
device are not limited to those illustrated in the drawings. The
whole or a part of each device may be distributed or integrated
functionally or physically in desired units depending on various
types of loads and usage, for example. The acquiring unit 40, the
calculating unit 41, the output unit 42, and the identifying unit
43 may be connected to the facility selection supporting device 10
as external devices via a network 14, for example. Alternatively,
the acquiring unit 40, the calculating unit 41, the output unit 42,
and the identifying unit 43 may be included in respective different
devices. In this case, the respective devices are connected via a
network to cooperate with one another, thereby achieving the
functions of the facility selection supporting device 10.
[0121] Facility Selection Supporting Program
[0122] The various types of processing described in the embodiments
can be performed by a computer, such as a personal computer and a
workstation, executing a computer program prepared in advance. The
following describes an example of a computer that executes a
facility selection supporting program having functions similar to
those of the embodiments with reference to FIG. 19. FIG. 19 is an
example block diagram for explaining the computer that executes the
facility selection supporting program.
[0123] As illustrated in FIG. 19, a computer 300 includes a central
processing unit (CPU) 310, a read only memory (ROM) 320, a hard
disk drive (HDD) 330, and a random access memory (RAM) 340. The
components 310 to 340 are connected to one another via a bus
400.
[0124] The ROM 320 stores therein in advance a facility selection
supporting program 320a that functions in the same manner as the
processing units in the embodiments described above. The facility
selection supporting program 320a functions in the same manner as,
for example, the acquiring unit 40, the calculating unit 41, the
output unit 42, and the identifying unit 43 in the embodiments
described above. The facility selection supporting program 320a may
be provided separately as appropriate.
[0125] The CPU 310 reads the facility selection supporting program
320a from the ROM 320 and executes the program, thereby performing
similar operations as the embodiments described above. That is, the
facility selection supporting program 320a performs similar
operations as the acquiring unit 40, the calculating unit 41, the
output unit 42, and the identifying unit 43.
[0126] The ROM 320 need not always store therein in advance the
facility selection supporting program 320a. Alternatively, the
facility selection supporting program 320a may be stored in the HDD
330.
[0127] The computer program may be stored in a "portable physical
medium" inserted into the computer 300, such as a flexible disk
(FD), a compact disc read only memory (CD-ROM), a digital versatile
disc (DVD), a magneto-optical disc, and an integrated circuit (IC)
card. The computer 300 may load the computer program from the
portable physical medium to execute the computer program.
[0128] Furthermore, the computer program may be stored in another
computer (or a server) connected to the computer 300 via a public
line, the Internet, a local area network (LAN), a wide area network
(WAN), or the like. The computer 300 may read each computer program
from these devices to execute the computer program.
[0129] The present invention can support selection of a
distribution facility that matches the electric load.
[0130] All examples and conditional language recited herein are
intended for pedagogical purposes of aiding the reader in
understanding the invention and the concepts contributed by the
inventor to further the art, and are not to be construed as
limitations to such specifically recited examples and conditions,
nor does the organization of such examples in the specification
relate to a showing of the superiority and inferiority of the
invention. Although the embodiments of the present invention have
been described in detail, it should be understood that the various
changes, substitutions, and alterations could be made hereto
without departing from the spirit and scope of the invention.
* * * * *